Telescopic positioner for induction heating coil



Feb. 10, 1970 1.. c. MILLER 3,

TELESCOPIC POSITIONER FOR INDUCTION HEATING COIL Filed NOV. 29, 1967 4 Sheets-Sheet 1 INVENTOR 460/V/0/45 C. M/MEZ A Tram/6V L. -c. M1LLER 3,495,063 TELESCOPIC POSITIQNER FOR INDUCTION HEATING COIL Feb. 10, 1970 4 Sheets-Sheet z N$ ms m \m\ m HMQ $3 mg m? m mg 3 y NQ L m R Q v m was M bNnm w R V m I. C)WI 4 Sheets-Sheet 5 L. C. MILLER TELESCOPIC POSITIONER FOR INDUCTION HEATING COIL Feb. 10, 1970 Fil ed No INVENTOR A'O/V/DAS C. M/e

Feb. 10, L. C(MILLER 3,

TELESGOPIC POSITIONER FDR INDUCTION HEATING COIL Filed Nov. 29, 1967 4 Sheets-Sheet 4 INVENTOR M/ZAEE "United States Patent Us. Cl. 219-10.7s 10 Claims ABSTRACT OF THE DISCLOSURE An apparatus for advancing and retracting an induction heating tool that avoids moving the energy leads of a coaxial cable by attaching the tool to a secondary coil which reciprocates within a secured primary coil connected to the cable leads.

This invention relates to an induction heating apparatus and is particularly directed to improvements in moving an induction heating tool to and from the work.

My prior Patent No. 2,866,880 was concerned with the connection of a water cooled induction coil to an induction heating machine. Another prior Patent No. 3,022,368 disclosed a coaxial cable using the above connection whereby high frequency electrical energy could be delivered from an induction heater to a remotely positioned tool. Such a tool is particularly suitable for the joining of metal parts by brazing. Unfortunately, constant movement of the coaxial cable will usually cause deterioration and a subsequent failure. Accordingly, to prevent this constant movement it has been necessary to bring the parts to a stationary tool, creating an inefiicient operation. a

It is the principal object of the present invention to provide a device to advance and retract the induction heating tool to the work without moving or flexing the coaxial cable.

Another object is to provide a device of this type which permits adjustment of the connections for the coaxial cable leads.

Another object is to provide a device of this type in which the current/voltage ratio may be easily adjusted.

Another object is to provide a movable secondary coil having optimum electrical characteristics.

Another object is to provide a device of this type using a single turn secondary coil having novel construction for coolant circulation.

In the drawings:

FIGURE 1 is a top plan view showing a preferred embodiment of this invention.

FIGURE 2 is a top plan View similar to FIGURE 1, showing the device in a retracted position.

FIGURE 3 is a longitudinal sectional elevation showing a portion of the device.

FIGURE 4 is a longitudinal sectional elevation showing another portion of the device.

FIGURE 5 is a fragmentary view partly in section taken substantially on the lines 55 as shown in FIG- URE 4.

FIGURE 6 is a transverse sectional elevation taken substantially on the lines 66 as shown in FIGURE 4.

FIGURE 7 is a sectional view taken substantially on lines'7 7 as shown in FIGURE 3.

Patented Feb. 10, 1970 ice FIGURE 8 is a perspective view showing a preferred embodiment of the single-turn secondary coil used in connection with this invention.

FIGURE 9 is a transverse sectional elevation taken substantially on the lines 9-9 as shown in FIGURE 5.

FIGURE 10 is a transverse sectional view taken substantially on the lines 10-10 as shown in FIGURE 3.

FIGURE 11 is a transverse sectional view taken substantially on the lines 11-11 as shown in FIGURE 8.

Referring to the drawings, the induction heating tool assembly, generally designated 10, includes a work coil 11, having several turns and preferably formed of copper tubing which may be square in cross-section and hollow to provide a passage for circulating a coolant. The ends 12 and 13 of the hollow copper tubing are brazed within parallel extension tubes 14 and 15, respectively. The ex tension tubes 14 and 15 are clamped in spaced relationship by means of the insulating clamp 16 and by means of threaded fastener 17.

The parallel extension tubes 14 and 15 are slidably mounted within the electrical conductors 18 and 19. The extension tubes 14 and 15 are held in place by tightening the nuts 20 and 21. When it is desired to remove the induction heating tool 10 or substitute a different tool it is only necessary to unscrew the nuts 20 and 21 and thereby permit axial movement of the tool 10.

A cylindrical plunger 22 receives electrical conductors 18 and 19. A filler cap 23 formed of electrically nonconducting material is mounted within the forward end of the plunger 22 and is held in place by threaded fasteners 24, which are also electrically nonconductive. Filler cap 23 has two circular openings 25 and 26 through which the electrical conductors 18 and 19, respectively, pass.

The electrical conductor 18 extends the entire length of the plunger assembly 22 and out through the circular opening 27 in a non-conductive filler cap 28, similar to cap 23. Cap 28 is also held in place by nonconductive threaded fasteners.

The center electrical conductor 18 is positioned in a pair of concentric tubes 29 and 30. The inner tube 29 is formed of electrically insulating material, while the outer tube 30 is of a metallic material.

Electrical conductor 19 is slidably fitted within the tubular conductor 31 and electrical connection is maintained by means of brazing 32. Conductor 31 is reduced to a semicircular shape at 33 and it is enlarged to its original circular shape at 34 before it receives tubular condoctor 35 which extends out through a circular opening 36 in filler cap 28.

A rectangular separator 39 spaces the outer tube 30 from the electrical conductor 31. Blocks 40 and 41 hold the conductor 31 in position and create an air gap 42 between the electrical conductor 31 and the metallic housing 43 which surrounds the entire cylindrical plunger 22. Insulating keys 44 prevent any relative movement of the tubular conductors 18, 19 and 35.

A rectangular manifold assembly generally designated 45, fits into the plunger assembly through a slot 46 in the housing 43. The manifold 45 is provided with two coolant passages 47 and 48 and may be connected to the electrical conductor 31 by means of brazing 49. Aligned openings 50 and 51 in the conductor 31 and the manifold 45,

respectively, establish communication between the coolant passage 47 in the manifold 45 and the passage 52 within the conductor 31. An O-ring 53 prevents leakage at the joint. Similarly, aligned openings 54 and 55 in the conductor 31 and manifold 45, respectively, establish communication between the coolant passage 48 in the manifold 45 and the passage 56 within the conductor 31. An O-ring 57 also prevents leakage at the joint.

The coolant which circulates through the reciprocating portion of the device, enters the manifold assembly 45 through the terminal 58 and into the passage 48. The coolant exits from passage 47 through terminal 59.

The manifold assembly 45 also includes a threaded rod 60 which extends through the center of the manifold 45 through the conductor 31 and abuts the insulator 39. Rod 60 is connected to a ground lug 61, which is connected to a ground cable 62.

Conductors 18 and 35 are connected to a secondary coil 63, by the tubular conductors 64 and 65, respectively. As shown in the drawings, this coil has only one turn, although a coil having more than one turn could be used. Tubular conductors 64 and 65 are slidably mounted within the conductors 18 and 35, and held in place by the nuts 66 and 67 respectively.

Both the secondary coil 63 and the plunger 22 are connected to a carrier assembly generally designated 68. The ends 69 and 70 of the carrier assembly 68 are formed of an electrically nonconducting material and held together by posts 71 and 72, which are also electrically nonconductive. The posts 71 and 72 are connected to the ends by screws 73 and 74, respectively. O-rings 75 and 76 of electrically nonconducting material are fitted around the circumference of the ends 69 and 70, respectively. The carrier assembly 68 slides back and forth on the outer surface of the O-rings 75 and 76.

The end 69 has two circular openings 77 and 78 which receive the metallic receptacles 79 and 80, respectively. Receptacles 79 and 80 have external threads which are engaged by the nuts 81 and 82 to hold the receptacles in position. The tubular conductors 64 and 65 are brazed within the receptacles 79 and 80, respectively. The receptacles 79 and 80 are in turn connected to the tubular openings 83 and 84, respectively. Tubular openings 83 and 84 are connected to terminal blocks 85 and 86, respectively. Terminal blocks 85 and 86 are rectangular in cross ssection and the lower ends fit into slots 87 and 88 in the tubular openings 83 and 84, respectively, and may be connected by means of brazing. Aligned ports in the tubular opening 84 and the terminal block 86, respectively, provide for the flow of coolant from a central passage in the tubular opening 84 into a passage 89 in terminal block 86. Aligned ports in the tubular opening 83 and the terminal block 85, respectively, provide for the flow of coolant from a passage 90 in terminal block 85 into a central passage in the tubular opening 83.

Included within the secondary coil 63 are a series of split rings 91, 92, 93, 94 and 95. Each ring is square in cross section and hollow to provide for the passage of coolant. 'Ends 96, 97, 98, 99 and 100 of the rings 91, 92, 93, 94 and 95, respectively, are mounted in rectangular slots in the terminal block 86 and may be connected to the terminal block 86 by means of brazing. Ends 101, 102, 103, 104 and 105 of rings 91, 92, 93, 94 and 95 are similarly mounted in and connected to rectangular slots in the terminal block 85. The terminal blocks 85 and 86 are separate and define the gap 106.

Aligned ports 107 and 108 in the terminal block 86 in the ring 91, respectively, allow for the flow of coolant from the passage 89 in the terminal block 86 to the passage 110 in the ring 91. Aligned ports 111 and 112 in the ring 91 and terminal block 85, respectively, allow the coolant to flow from pasasge 110 in ring 91 into the passage 109 in the terminal block 85. The coolant then flows through the end 102 into the hollow ring 92 out through end 97 into a passage in terminal block 86 through end 98 into ring 93 out end 103 into a passage in terminal block through end 104 into ring 94 out end 99 into a passage in terminal block 86 through end into ring 95 out end and into passage 90 in the terminal block 85.

The carrier assembly 68 is advanced and retracted by a fluid motor assembly, generally designated 113. A Tef- Ion-coated piston 114 is coaxially fitted around the circumference of the housing 43 and held in place by the keys 115 and 116. The piston 114 is composed of two cylindrical parts 117 and 118 and separated by an O-ring 119.

A metallic cylinder 120 is in contact with the outer surface of the piston 114 and an air gap 121 separates the cylinder 120 from the housing 43, and it is within air gap 121 that the piston 114 advances and retracts. At each end of the cylinder 120 are internal threads 122 and 123. At the front end the cylinder 120 receives an externally threaded cap 124. An O-ring 125 prevents leakage at the joint. Another O-ring 126 prevents leakage between the housing 43 and the cap 124.

The cap 124 is provided with a threaded circular opening 127 which engages a terminal 128. Terminal 128 is provided with a passage 129 which opens into the gap 130. Another externally threaded cap 131 is received by the internal threads 123 of the cylinder 120. An O-ring 132 prevents leakage at the joint. Another O-ring 133 prevents leakage between the cap 131 and the housing 43. A circular opening 134 with internal threads receives a terminal 135. The terminal 135 is provided with a passage 136 and aligned ports in the terminal 135 and cap 131, respectively, establish communication between a fluid passage in the terminal 135 and the passage 137 in the cap 131. Passage 137 opens into a cavity 138.

To advance or retract the carrier assembly 68, fluid, such as air, is forced into one of the terminals and exhausted out the other terminal, thus increasing the fluid pressure on one side of the piston 114 while reducing the fluidpressure on the opposite side.

A switch assembly, generally designated 139 is used to control the timing of theadvance or retraction of the heating tool assembly 10 and also operates as a cut-off for the energy transmitted through the tool assembly 10. A circular stop rod 140 extends through a circular opening in the electrical switch housing 141 and it is held in a flexible position by the compression springs 142 and 143 which are spaced between the housing 141 and the keys 144 and 145, respectively.

A guide 146 which is attached to the manifold assembly 45 by screws 147 has a circular opening 148 and slides along the stop rod 140. Two metallic stops 149 and 150 are attached to the stop rod 140 and are held in position by threaded fasteners 151. Between 152 and 153, the stop rod is reduced in diameter. As the induction heating tool assembly 10 retracts or advances the guide 146 also retracts or advances and contacts one of the stops 149 or 150 which in turn move the stop rod 140 causing the lever arms 154 and 155 to fall to or rise from the reduced diameter in the stop rod 140. Thus, actuating a conventional mechanism (not shown) for controlling the flow of fluid in the fluid motor and current in the tool assembly.

A stationary cylindrical sleeve 156 is formed of insulating material and connected to the cap 131 by screws 157. The inner surface of the sleeve 156 is in contact with the O-rings 69 and 70, and the carrier assembly 68 moves axially within this cylindrical sleeve 156. The sleeve 156 is provided with a rectangular slot 158 which allows the manifold assembly 45 to move freely. An electrically nonconducting spacer 159 is connected to the end of sleeve 156 by screws 160. This spacer 159 has a central opening 161 with internal threads which receive a threaded fastener 162 which secures the sleeve 156 to a stationary support 163.

The sleeve 156 is positioned within the primary coil assembly, generally designated 164. At each end of the Coil assembly are the rings 165 and 166 which are attached to the primary coil housing 167 by nylon screws 168 and 169, respectively. The primary coil assembly 164 is clamped in position by tightening the screws 170 and 172. By loosening screws 170 and 172, the primary coil assembly 164 may be adjusted axially or circumferentially to any convenient position for location of the coaxial leads. This axial adjustment with respect to the secondary coil 63 also permits the volt-ampere ratio to be varied.

Between 'the sleeve 156 and the primary coil housing 167 are stationed the hollow primary coils 173. The ends 174 and 175 of the primary coil are aligned with the central passages 176 and 177, respectively, of the electrically conducting posts 178 and 179. O-rings 180 and 181 prevent. leakage at the joints. The posts 178 and 179 are connected to the coil ends 174 and 175 by means of brazing 180a and 181a. Rectangular support conductors 182 and 183 with coolant passages 184 and 185, respectively, are connected to the posts 178 and 179.

Aligned ports 186 and 187 in the conductor 182 and the post 178, respectively, establish communication between the coolant passage 184 in the conductor 182 and the central passage 176 within the post 178. An O-ring 188 prevents leakage at the joint. Aligned ports 189 and 190 in the conductor 183 and post 179, respectively, establish communication between the coolant passage 185 in the conductor 183 and the central passage 177 within the post 179. An O-ring 191 prevents leakage at the joint.

Rectangular block 192 formed of electrically insulating material is attached by screws 193 to the conductors 182 and 183 and holds them in a spaced position. Terminals 194 and 195 for the coaxial leads are connected to the conductors 182 and 183, respectively, by screws 196. Hollow passages 197 and 198 within the terminals 194 and 195, respectively, provide for the flow of coolant through the terminals and to the conductors 1 82 and 183. O-rings 199 and 200 prevent leakage at the joints.

Having fully described my invention, it is to be understood, that I do not wish to be limited to details herein set forth, but my invention is of the full scope of the appended claims.

I claim:

1. In a device of the class described, the combination of: a primary coil and secondary coil, means whereby the ends of said primary coil may be connected to electrical leads, a stationary sleeve positioned coaxially within said primary coil and formed of insulating material, means securing the primary coil with respect to said sleeve, a carrier mounted to reciprocate within said sleeve, means securing and secondary coil to said carrier to move as a unit therewith, a pair of paralel tubes comprising electrical conductors insulated from each other and secured to said carrier and projecting axially from said stationary sleeve, means at the projecting ends of said tubes for'connection to a work coil, means connecting said electrical conductors to said secondary coil, and means for reciprocating said carrier and tubes.

2. The combination set forth in claim 1 in which the secondary coil has only a single turn.

3. The combination set forth in claim 1 wherein the primary coil may be adjustably positioned axially of said stationary sleeve.

4. The combination set forth in claim 1 in which coolant passage means are provided in said secondary coil and in said electrical conductors for circulating a coolant therethrough.

5. In a device of the class described, the combination of: a primary coil and secondary coil, means whereby the ends of said primary coil may be connected to electrical leads, a stationary sleeve positioned coaxially within said primary coil and formed of insulating material,

means securing the primary coil with respect to said sleeve, a carrier mounted to reciprocate within said sleeve, means securing said secondary coil to said carrier to move as a unit therewith, a pair of electrical conductors insulated from each other and secured to said carrier and projecting from said stationary sleeve, means at the projecting ends of said conductors for connection to a work coil, means connecting said electrical conductors to said secondary coil, means for reciprocating said carrier including a plunger mounted coaxialy on said stationary sleeve and secured relative to said electrical conductors, and with fluid pressure means for reciprocating said plunger.

6. In a device of the class described, the combination of: a primary coil and secondary coil, means whereby the ends of said primary coil may be connected to electrical leads, a stationary sleeve positioned coaxially within said primary coil and formed of insulating material, means securing the primary coil with respect to said sleeve, a carrier mounted to reciprocate within said sleeve, means securing said secondary coil to said carrier to move as a unit therewith, a pair of parallel tubes comprising electrical conductors insulated from each other and secured to said carrier and projecting axially from said stationary sleeve, means at the projecting ends of said conductors for connection to a work coil, means connecting said electrical conductors to said secondary coil, and means for electrically coupling and decoupling said work coil to a work piece.

7. In a device of the class described, the combination of: a primary coil and a secondary coil, means whereby the ends of said primary coil may be connected to electrical leads of a coaxial cable, stationary sleeve positioned coaxially within said primary coil and formed of insulating material, means for adjustably securing the primary coil in axial position with respect to said sleeve, a carrier mounted to reciprocate within said sleeve, means securing said secondary coil to said carrier to move as a unit therewith, a pair of parallel tubes comprising electrical conductors insulated from each other and secured to said carrier and projecting axially from said stationary sleeve, means at the projecting ends of said conductors for detachable connection to a work coil, means connecting said electrical conductors to said secondary coil, means for reciprocating said carrier, said means including a plunger mounted coaxially of said stationary sleeve and secured relative to said parallel tubes, and means for reciprocating said plunger.

8. The combination set forth in claim 7, together with fluid pressure means for reciprocating said plunger.

9. In a device of the class described, the combination of: a primary coil and a secondary coil, means whereby the ends of said primary coil may be connected to electrical leads of a coaxial cable, a stationary sleeve positioned coaxially within said primary coil and formed of insulating material, means for adjustably securing the primary coil in axial position with respect to said sleeve, a carrier mounted to reciprocate within said sleeve, means securing said secondary coil to said carrier to move as a unit therewith, a pair of electrical conductors insulated from each other and secured to said carrier and projecting from said stationary sleeve, means connecting said electrical conductors to said secondary coil, means at the projecting. ends of said conductors for detachable connection to a work coil, means for reciprocating said carrier, and means for electrically coupling and decoupling said work coil to a workpiece.

10. In a device of the class described, the combination of: a primary coil and a secondary coil, means whereby the ends of said primary coil may be connected to electrical leads, a stationary sleeve positioned coaxially within said primary coil and formed of insulating material, the sleeve having an axially extending slot, means securing the primary coil with respect to said sleeve, a carrier mounted to reciprocate within said sleeve, means securing said secondary coil to said carrier to move as a unit therewith, a pair of electrical conductors insulated from each other and secured to said carrier and projecting from said stationary sleeve, means at the projecting ends of said conductors for connection to a work coil, means connecting said electrical conductors to said secondary coil, and means for reciprocating said carrier, said means including a plunger mounted coaxially of said stationary sleeve and secured relative to said elec- 1 References Cited UNITED STATES PATENTS 0 JOSEPH V. TRUHE, Primary Examiner L. H. BEN'DER, Assistant Examiner U.S. C1.X.R. 

